Education

Ph.D. The Ohio State University, 1988
M.S. The Ohio State University, 1984
B.S. The University of Akron, 1981

Research Interests

My research involves the study of foraminifera, especially planktonic foraminifera, and what they can tell us about how Earthâ€™s environment has changed during the past 120 million years. Because of their small size, relatively short geologic age ranges, and wide distribution in a variety of marine sediments worldwide, study of foraminiferal assemblages provides valuable insight to the age of the sediments in which they are found (biostratigraphy), the type of environment in which they were deposited (paleoecology), and the temperature of the ocean water in which they grew (paleoclimatology and paleoceanography). Biostratigraphic analysis require species identification and calculation of sedimentation rates using age calibrations for the evolutionary appearances and extinctions of species from different fossil groups, paleomagnetic reversal events, carbon and oxygen isotopic events, and constraints using radiometric and strontium isotopic data. These are plotted on age-depth curves such as those provided by CHRONOS. Insight into paleoecologic change is gained through quantitative analysis of species assemblages through time as well as through study of shell geochemistry. Oxygen isotope analyses of well preserved foraminiferal shells are especially useful for determination of relative paleotemperature changes of the ocean bottom (using benthic foraminifera) and the ocean surface (using planktonic foraminifera). For all of my studies, accurate species identification is a necessity. This has led to my participation in several taxonomic working groups and development of taxonomic atlases and databases that are accessible through the internet.

Global Change Research on Short and Long Time Scales

Long-term (>3 million year) stable isotope records provide valuable insight to major shifts in global climate, organic carbon burial rates, and ocean circulation. Oxygen isotope paleotemperatures from benthic (bottom dwelling) foraminifera that lived below 500 m water depth can be used to characterize the global climatic state. If the benthic temperature estimates fall below 10ÂºC then we can assume that winter temperatures at polar latitudes fell below freezing. If the deepwater temperatures fall below 5ÂºC then continental ice sheets probably existed at polar latitudes. On the other hand, if deepwater temperatures were greater than 15ÂºC then we can assume that no permanent ice existed and winter freezing at polar latitudes is unlikely. Examples of long-term climate change are presented for deep sea (>1000 m) sites the subtropical western Atlantic and for sites poleward of 58ÂºS around Antarctica. The subtropical deepwater temperatures shown on the Blake Nose graph and the surface water temperatures on the southern high latitudes graph both indicate that the middle through Late Cretaceous was a time of extreme global climatic warmth. The temperature maximum during the Cretaceous occurred about 94-89 million years ago, with surface water temperatures estimated as warm as 32ÂºC at 58ÂºS paleolatitude. Deepwater (>1000 m) temperatures for that time are estimated to have been between 15 and 20ÂºC, which is far warmer than modern day deep water termperatures averaging less than 2ÂºC. This â€œSupergreenhouseâ€� climate marks the most extreme global warmth known to have occurred during the past 250 million years, supporting growth of lush forests, large dinosaurs and other temperature sensitive organisms at both poles. It probably resulted from much higher concentrations of carbon dioxide and other greenhouse gases that were expelled into the atmosphere during a long period of undersea volcanic activity.

Short-term (<3 million years) stable isotope data provide a higher resolution record of ocean and climate change. Such studies enable better understanding of the rates of biotic, climatic and oceanic response to external forcing and help identify what those forcing mechanisms were. One example is presented for the Aptian/Albian boundary interval from ODP Site 1049 on Blake Nose. In this detailed oxygen and carbon isotope record, the diamonds represent isotopic values from benthic foraminifera and the other symbols represent different species of planktonic foraminifera. The data reveal several interesting new insights: (1) there was much greater short-term variation of climate and ocean change than was previously recognized; (2) the vertical temperature gradient was quite low with the exception of the Oceanic Anoxic Event 1b, which is represented by a black shale in the lower Albian; (3) stable isotope values of several planktonic species plot with co-occurring benthic suggesting that either they lived below the surface mixed layer or the isotopic composition of their shells was not in equilibrium with the isotopic composition of the surrounding water. The abrupt carbon isotopic shift at the Aptian/Albian boundary coincides with the extinction of several long-lived Aptian species and their replacement by low diversity, small-sized species with simpler shell morphologies. The cause of the isotopic shift and species turnover is the focus of current investigations.

The Cretaceous/Tertiary Extinction and Recovery

Evidence that links mass extinctions at the end of the Cretaceous Period in both marine and terrestrial extinctions with the impact of a ten kilometer diameter asteroid at the Chicxulub Crater (Yucatan Peninsula) is overwhelming. Nonetheless, some researchers have argued that other factors played a significant role in causing planktonic foraminiferal extinctions below and above the boundary level. Using a variety of methods, including foraminiferal species abundance counts, measurements of shell size/mass ratios, stable oxygen and carbon isotopes analyses, and strontium isotope analyses, my study of several complete Cretaceous/Tertiary (K/T) boundary has demonstrated that (1) the pre-boundary extinction rate is not unusually high; (2) the greatest change in population structure, specimen size distributions, and species composition exactly coincide with deposition of a single asteroid impact layer; (3) post-K/T occurrences of all but three Cretaceous species can be attributed to reworking (based on comparative analysis of foraminiferal shell geochemistry across the boundary interval), and (4) planktonic foraminifera suffered a 92% extinction rate, which is the highest in their entire evolutionary history.

Field Studies in Tanzania.

During the past several years I have joined Paul Pearson (University of Cardiff) and other members of the Tanzania Drilling Project (TDP) to obtain sediment samples from southeastern Tanzania where impermeable, clay-rich intervals yield some of the worldâ€™s best preserved tropical foraminifera of Cretaceous through Oligocene age. Using a portable drilling rig the TDP has been able to obtain cores with much greater stratigraphic continuity and better preservation than is possible from the sampling of outcrops. Core description, core sampling, microfossil processing and foraminiferal species identification are routinely done at the rig location. Acquisition of pristinely preserved foraminifera is highly desirable for paleoclimatic and paleoceanographic studies as the chemistry of their shells has not been altered from the original composition. The goal is to obtain oxygen isotope data that can be used to estimate surface and deep water temperatures at low latitudes for reconstruction of Cretaceous latitudinal temperature gradients and for interpretation of the depth ecology of Cretaceous planktonic foraminifer species.

Wendler, Ines, Huber, Brian T., MacLeod, Kenneth G. and Wendler, Jens E. 2011.
Early evolutionary history of Tubulogenerina and Colomia, with new species from the Turonian of East Africa, Journal of Foraminiferal Research, 41(4):384-400

Snyder, S. W. and Huber, Brian T. 1996. "Preparation techniques for use of foraminifera in the classroom". Pp. 231-236 in Learning from the fossil record (Scotchmoor, J. and McKinney, F. K.). The Paleontological Society Papers

Huber, Brian T. and Watkins, D. K. 1992. "Biogeography of Campanian-Maastrichtian calcareous plankton in the region of the Southern Ocean: paleogeographic and paleoclimatic implications". Pp. 31-60 in The Antarctic Paleoenvironment: A Perspective on Global Change, Antarctic Research Series (Kennett, J. P. and Warnke, D. A.). American Geophysical Union

Pospichal, J. J. and Huber, Brian T. 1992. "The Cretaceous/Tertiary boundary in the southern Indian Ocean: results from the coring operations of the Ocean Drilling Program". Pp. 275-294 in Synthesis of Results from Scientific Drilling in the Indian Ocean, Geophysical Monograph 70 (Kidd, R. B. and Rea, D. K.). American Geophysical Union